I typically don't ask a lot of questions at an interview. I let the interviewer take the lead. Usually they'll start out explaining what the position entails, then launch into a bunch of canned questions that they're required to ask by the agency they work for. After that, they'll ask me if I have any questions. I'll ask about what the orientation process looks like, whether scrubs
are provided or if we buy our own, or in the case of a per diem position, what kind of time commitment the manager is hoping for (2 shifts a week, 4 shifts a month, etc.).
Usually the interviewer has already made up their mind if they want to hire me or not by the time they get to the point of asking me if I have any questions. They're judging by my answers to their questions as well as my nonverbal communication. Do they feel I'm being honest with them? Do they feel I'm really interested in this position? Do they feel I "get" the core values of the organization? Do I seem confident and competent without coming off as cocky? Will I be a good fit within their unit? They figure all of this out within the first few minutes of the interview.